I am in manual mode (M on the top left scroll wheel above the on button) using a sigma 10-20mm F4-5.6 and then I spin the scroll wheel (which has a "set" button in the middle) below the 'q' button, the aperture doesn't change.

It also won't change in Aperture priority mode (AV Mode)

I am a noob with cameras, so I am really stumped

  • 2
    Have you checked the control wheel isnt "locked" (the button underneath saying "unlock") Jul 31, 2015 at 10:24
  • Great, i have made an answer below, it would be great if you could mark it as correct :-) Jul 31, 2015 at 10:27

2 Answers 2


It sounds like your control wheel is "locked" - press the button underneath it called "unlock" This should now let you control the aperture.


Digital Lightcraft gave the correct answer but I'd like to add that you can disable the automatic locking from the menu - the fourth tab from the right, lowest item ("Lock" and a wheel icon).

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